FIGURE 12-2 -A Thick Uniform Beam Is Balanced on a Pivot as a Pivot

FIGURE 12-2
-A thick uniform beam is balanced on a pivot as shown in Fig. 12-2 where it is in equilibrium. Which type of equilibrium is this and why is it of that type?

A) Stable. When the beam tilts slightly to one side, the center of mass moves to the same side resulting in torque that will cause rotational acceleration in the opposite direction of the slight displacement.
B) Unstable. When the beam tilts slightly to one side, the center of mass moves to the same side resulting in torque that will cause further rotation in that direction.
C) The type of stability depends on the mass and length of the beam. Until those values are known, the stability cannot be evaluated.
D) Neutral. A tilt of the beam does not change the torque that is acting on the body and the total torque will remain zero as it is in equilibrium.
E) Stable. All equilibria are stable when a single support is below the center of mass. The equilibria are only unstable or neutral when the support is under one corner of the object.